The way I read the text, it actually doesn't get rid of focus powers. This makes it quite powerful. It says "The elemental schools don’t have focus powers or resonant powers." Note that it doesn't say that the jin don't have the focus powers, just that the elemental schools don't provide new ones. This is emphasised in implement mastery, when it refers to the DCs of focus powers, among other things. Unfortunately, implement mastery also gives your elementals hardness 20, so maybe they didn't read it too well. Feel free to correct me if I'm wrong though.
